Various latching systems are known for latching together housings of opposing electrical connectors being mated to engage mating pairs of contact terminals secured therein. When one of the connectors is a right angle connector mounted to a circuit board, the latching system needs to be provided at either the two ends of the connector or along a common side parallel to a circuit board. To minimize real estate on the circuit boards it is more desirable to have a latching system that is on a common side of the housings. U.S. Pat. No. 5,344,335 discloses one such latching system in which one of the connectors includes a latch arm having a spaced apart pair of latches, each being received in latching slots on the other connector near the lateral ends of the connectors. This type of latching system, however, requires additional height beyond the housing envelope of the connector, which may interfere with stacking the connectors close together. In those instances where it is desirable to have an array of connectors in a closely stacked arrangement, such as a card cage, for example, it is desirable to have a latching system that essentially functions within the envelope of the housing walls and one that furthermore provides a clear indication that the housings are in a full mated condition. It is also desirable to provide a latching system that can minimize that possibility of incomplete latching and incomplete mating.